Method:1. Preheat the oven to 170C/325F/mark 3. Grease and line an 9x13 inch pan.

2. For the brownie layer, place the butter in a small saucepan and heat gently until completely melted. Set aside to cool.

3. In a large bowl, mix together the eggs, sugar and salt. Once the mixture has become thick and more pale, fold in the chocolate mixture. Sift in the flour, add the vanilla and mix thoroughly. Pour the mixture into the prepared pan. Bake for 25-30 minutes, then allow to cool completely.

4. For the brown butter layer, place the butter in a small saucepan and heat gently until melted. Continue to heat until the butter browns. Transfer to a small bowl, then mix in the icing sugar, cream and vanilla. Spread over the brownies.

5. For the glaze, melt the butter and chocolate together in a heatproof bowl in the microwave oven or over a pan of simmering water. Pour over the brownies and chill until set.